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Recent advances in the quantitation of human fetal hemoglobins with different gamma chains
Author(s) -
Huisman T. H. J.,
Wilson J. B.
Publication year - 1980
Publication title -
american journal of hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.456
H-Index - 105
eISSN - 1096-8652
pISSN - 0361-8609
DOI - 10.1002/ajh.2830090211
Subject(s) - fetal hemoglobin , high performance liquid chromatography , chemistry , chromatography , residue (chemistry) , hemoglobin , in vitro , biochemistry , fetus , biology , genetics , pregnancy
Three types of γ chain of human hemoglobin (Hb) F have been discovered. The γ and A γ chains differ at position 136 (glycine in G γ; alanine in A γ) and are the products of nonallelic genes. The T γ chain is found in rather high frequency in certain world populations, and is characterized by a threonyl residue at position 75 replacing the commonly occurring isoleucyl residue. Convincing evidence is present that the T γ chain is the product of an allele of the A γ chain gene, and should be renamed A γ T chain. Thus, the three γ chains are G γ I , A γ I , and A γ T . Until recently, the presence and the quantity of these chains were determined by chemical analyses of the tryptic peptides of the isolated Hb F. These procedures involve chromatographic separations or fingerprinting methods. The introduction of high pressure liquid chromatography (HPLC) has greatly facilitated the separation of these peptides. Since minute quantities are required, the latter method is ideally suited for the identification of the Hb F produced in in vitro cell colonies. Electrophoretic and chromatographic (HPLC) methods have been developed which make it possible to separate the G γ and A γ chains in small amounts of Hb F (less than 0.5 mg). These procedures allow accurate quantitation of the G γ/ A γ ratio in the Hb F and may also be suitable for in vitro biosynthetic analyses. One of the HPLC procedures has been modified so that the three types of γ chain can be quantitated in one single chromatographic experiment. Examples of separations are provided, details of some of the methods are discussed, and their applicability illustrated.